Objective: The aim of this study was to search for potential markers in the subthalamic nucleus activity of parkinsonian patients associated with levodopa-induced dyskinesias in typical and early onset of disease.

Background: Levodopa induced dyskinesias (LIDs) are the main indication for deep brain stimulation (DBS) therapy in patients with Parkinson’s disease (PD). While LIDs are common in typical PD, patients with the onset of PD before the age of 40 are thought to be especially prone to the LID development. However, patients with PD differ markedly in the duration and dosage of levodopa that lead to dyskinesias development, as well as in the form and severity of dyskinesias after drug administration. While features of LFP activity associated with hypokinetic motor symptoms in PD are extensively studied, less is known about potential electrophysiological markers associated with LIDs.

Method: Here we studied LFP recordings in the STN during DBS surgeries in 34 patients, including 17 persons with early onset PD. Preoperatively, all the patients were examined by a neurologist. UPDRS4 scores were used to evaluate the severity of drug therapy complications and to split the patients into two groups with low score (UPDRS4<11) and high score (UPDRS4>=11) of complications. Spectral features of LFP in 8-40 Hz range were accessed after extraction of aperiodic broadband component. To search for the differences, we compared the maximal values of flattened LFP spectra within a 4 Hz sliding window with 2 Hz steps along the range of interest.

Results: We have found that while UPDRS4 as well as UPDRS3 (off-state) scores were comparable in two groups with different age of onset, beta oscillations in the range of 20-26 Hz were significantly higher in early onset, than in typical PD. When comparing low and high UPDRS4 score groups, we have found significant differences in LFP power in 28-38 Hz range, that were observed for both early onset and typical PD.

Conclusion: We may state that both age at disease onset as well as the severity of drug therapy complications may affect spectral features of LFPs in the subthalamic nucleus (STN of parkinsonian patients and are needed to account for while searching for electrophysiological markers for adaptive DBS.
This study was supported by Russian Science Foundation (RScF 21-75-10152)

« Back to MDS Virtual Congress 2021

MDS Abstracts - https://www.mdsabstracts.org/abstract/lfp-spectral-features-associated-with-therapy-complications-in-typical-and-early-onset-parkinsons-disease/